ARTIGOS CIENTÍFICOS PARASITOLOGIA. Diagnóstico sorológico de erliquiose canina com antígeno brasileiro de Ehrlichia canis. Serological diagnosis of. 5 jun. Introdução Erliquiose Canina Picada do carrapato Conclusão Argélia – Patogenia Hematologia – anemia arregenerativa Diagnóstico Uso. Erliquiose canina. 92 likes. A erliquiose canina é uma importante doença infecciosa transmitida pelo carrapato Rhipicephalus sanguineus (carrapato marrom).
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Ehrlichiosis is a zoonotic disease that is caused by bacteria of the genus Ehrlichia.
The aims of this study were to detect the presence of Ehrlichia spp. Furthermore, this study identified factors associated with exposure to the agent in dogs in this locality. Blood samples were collected from dogs and submitted for indirect immunofluorescent assay and polymerase chain reaction testing caninz the detection of Ehrlichia spp.
Additionally, a peripheral blood smear was obtained from the ear tip for parasite identification. Of the animals, The dogs positive in one of the three techniques were considered exposed Younger dogs and rural habitat were protective factors and presence of ticks and contact with other dogs were the risk factors associated with exposure to the agent. Ehrlichiosis is an infectious disease that is caused by a gram-negative bacterium of the genus Ehrlichiawhich includes species such as E.
Canine monocytic ehrlichiosis is caused by E. This bacterium mainly parasitizes the cells of the mononuclear phagocyte system and causes clinical and hematological abnormalities such as fever, anorexia, vomiting, diarrhea, petechial hemorrhages, anemia, and thrombocytopenia MOREIRA et al.
Some factors may predispose dogs to disease development, such as older age, the presence of and contact with other dogs, living in urban habitats, and exposure to R. Studies of canine ehrlichiosis have become the focus of several research programs within Brazil. The increasing interest of researchers in conducting studies about this disease is due to the high morbidity and mortality of canine ehrlichiosis in Brazil.
Thus, the objectives of this study were canins determine the canine positivity for Ehrlichia spp. The city has a total area of km 2with approximately 26, inhabitants at a density of The study included a non-probabilistic sample of domiciled adult dogs aged one year or older.
The sample size calculation was performed using the Epi Info 3. The sample collection was conducted between May and September and was distributed evenly throughout the neighborhoods of erlichlose city, covering both rural 56 animals and cannina dogs areas.
The population proportion of each district in relation to the total population was determined. For each house visited, a maximum of two cannia were evaluated. The dog owners who participated in the study completed an epidemiological questionnaire, from which was acquired information about factors that could act as risk factors for infection, such as the presence of ticks, contact with other dogs, habitat, age, and gender.
The dog owners were older than 18 years of age and, at the time of the visit, were responsible for the household.
After the dogs were physically restrained, 8 mL of canine venous blood was collected by puncture of the jugular or cephalic vein. Five milliliters were dispensed into plastic tubes with an anticoagulant EDTAand 3 mL was dispensed into tubes without an anticoagulant.
Subsequently, the detection of anti- E. Samples that tested positive were subjected to serial dilutions in two basis until negativation. The negative and positive controls used for the dogs were canine sera on which serology had been performed in a prior study CARLOS et al.
Subsequently, to identify the species E. Checking for the presence of the bands was performed with the aid erlichlose a transilluminator Cxnina Biotecnologia. The blood smears were examined to detect Ehrlichia spp. To analyze the risk factors, all animals exposed to agent were considered seropositives on IFA or positives on blood-smear examination or nested-PCR testing.
Non-conditional logistic regression was performed, with the final model created through the output variables of the system backward.
Serology IFA yielded positive results in The nested-PCR test showed positive results in 97 Of the positive animals, 20 Of the study dogs, Compared with serology, the sensitivity and specificity of blood-smear examination were Together, the three diagnostic techniques used in this study had low values of sensitivity and high values of specificity in all cases.
Results were compared between diagnostic techniques. On blood-smear examination and serology, 27 dogs were positive with the first technique and negative with the second, whereas animals were positive with the second technique and negative with the first Figure 1.
On blood-smear examination and nested-PCR testing, 15 animals tested positive withthe first test and negative with the second, whereas 65 dogs were identified as positive withthe second technique and negative with the first Figure 1. On the IFA and nested-PCR test, 70 dogs were positive with the first diagnostic technique and negative with the second, whereas 43 dogs were positive with the second technique and erlichuose with the first Figure 1.
The canima associated with exposure to the agentof canine ehrlichiosis were age, habitat, contact with other dogs, and the presence of ticks. Dogs younger than four years of age and those living in rural areas were factors that protected a dog from exposure. Dogs that had any contact with other dogs residents or not and those that were parasitized by the ticks of R. Positive dogs were identified by blood smear, serological and molecular tests.
This study found that The first study was conducted using blood samples of pet dogs treated at the Veterinary Hospital of the State University of North Fluminense Darcy Ribeiro. The canins included in the study by Moreira et al. Diagnosis of Ehrlichia spp. Morulae in leukocytes are more abundant in the acute phase of the disease, and caninq is more likely with higher parasitemia.
Therefore, the low frequency of positive results obtained with the blood smears in this study may be explained by the higher chance of false negatives. However, false positives can also occur, because other structures may be mistaken for the morulae or inclusions of Ehrlichia spp. On IFA, the erlihciose However, it was lower than the values found by Nakaghi et al.
This may explain the high seropositivity of these animals. These researchers collected samples from dogs treated at the Veterinary Hospital of the State University of Santa Cruz and in private veterinary clinics, as well as from domestic dogs through random home visits. These results indicated that although the municipalities are near each other approximately km the rates of positivity for E.
Thus, the possibility of contact between dogs, including street dogs, facilitates exposure to the vector of infection and increases the number of positive tests for E.
In contrast, the animals studied by Carlos et al. When comparing the sensitivity and specificity of the blood-smear and serologic techniques, we noted that the chances of false-negative results with the blood-smear technique were high, whereas the chances of false positives erlichiosee low.
However, authors assert that other structures can be confused with morulae of Ehrlichia spp. The sensitivity of examination of the blood smear depends on the stage of infection of the animal at the time of the sampling. In the initial phase, when there is a higher parasitemia, there are more chances of finding infected leukocytes in the blood smear; however, in the subclinical and chronic phases of the disease, the chances of finding infected leukocytes decrease, which can result in false-negative results.
However, the probability of detection of specific antibodies increases, because IFA detects anti- E. The nested-PCR test identified 43 positive animals that did not have detectable levels of anti- E. This finding may be explained by the fact that diagnosis by IFA is more effective in the advanced stages of the disease, with reduced sensitivity in the initial phase of infection leading to false negatives. The absence of E. In addition, the IFA can also generate cross-reactivity with other Anaplasmataceae agents.
Serological diagnosis of canine monocytic ehrlichiosis with Brazilian antigen of Ehrlichia canis
Molecular studies indicate that new strains of Ehrlichia spp. These data indicate the possibility of agents showing similar genotypes to E.
Thus, there is erljchiose for further studies for confirmation. This may also explain the absence of detection of E. In addition to the above mentioned points, because serological testing identifies only antibodies, a positive case on serology may appear negative on PCR testing because of eradication of the Ehrlichia organisms by the immune system.
In this sense, the use of broad-based primers and then sequencing analysis of the positive samples for Ehrlichia sp. However, this was not the focus of erlihciose research, which aimed to detect the DNA of only the E. Thus, the absence of sequencing analysis prevented better use and interpretation of results.
Of the dogs evaluated, 16 had positive results with all of the diagnostic techniques, and had negative results in all of them. The results obtained in this study support the conclusion that the methods are complementary, because the different cainna techniques exhibited differences in the sensitivity and specificity for different stages of infection. The risk factors associated with exposure to the agent in this study were corroborated by Azevedo et al. Therefore, young dogs may be protected from infection because older animals have greater contact time with the bacteria over the course of their lives AZEVEDO et al.
Additionally, dogs from rural areas hada lower probability of acquiring the disease compared with dogs from urban areas, a result that was also observed by Aguiar et al. The occurrence of R. According to Azevedo et al. The transmission of ehrlichiosis by the tick vector requires the presence of an infected dog, so increased contact between dogs increases the chances of exposure to a tick vector infected with E.
This result is expected because R.
The analysis of the sensitivity and specificity of the diagnostic methods used in this study suggests that the complementary use of these tests will assist in the confirmation of Ehrlichia spp. Prevalence of Ehrlichia canis Rickettsiales: Anaplasmataceae in dogs and Acari: Ixodidae ticks from Brazil. Rhipicephalus sanguineus J Med Entomol ; 44 1: Serological cross-reactivity between and an species in naturally and experimentally infected cattle.
BMJ ; Molecular and serologic detection of spp. Ehrlichia J Wildl Dis ; 46 3: Arthropod-borne pathogens circulating in free-roaming domestic cats in a zoo environment in Brazil. Ticks Tick Borne Dis ; 5 5: Molecular detection of tick-borne bacterial agents in Brazilian and exotic captive carnivores.